Exsanguination, authored by G.R. Loreweaver, emerges as a thrilling foray into the realms of dark fantasy and horror, adeptly interweaving elements of suspense and mystery. The novel, set against a grim, dystopian backdrop, delves into the lives of its protagonists, Eleanor and Marcus, who find themselves in the heart of a foreboding urban landscape plagued not only by crime but by a sinister anomaly affecting its denizens.

The narrative begins with Eleanor, a young forensic pathologist, embroiled in a series of perplexing cases where victims appear entirely drained of blood. Marcus, a seasoned detective with shadows in his own past, is drawn into the mystery when the inexplicable deaths begin to sport patterns that hint at something beyond mere coincidence or the range of normal criminal activity. Here, Loreweaver's prowess in character development shines as he crafts Eleanor and Marcus with depth and relatability. Their dynamic, fraught with personal demons and professional pressures, adds a compelling layer to the overarching enigma they endeavor to unravel.

Loreweaver uses a rich, descriptive style that brilliantly captures the oppressive atmosphere of the setting – a city teetering on the brink of collapse, its streets shrouded in ever-present fog and darkness, almost palpable through his vivid descriptions. The city not only serves as a mere backdrop but almost as a character unto itself, contributing significantly to the mood and the stakes of the narrative. The imagery he employs is stark and often unsettling, serving the tone and theme of the book well.

The plot of Exsanguination is tightly woven with twists and turns that keep the reader on edge. Loreweaver excels in pacing the revelations, effectively maintaining suspense throughout the narrative. The concept of exsanguination (being drained of blood) is explored not just literally but metaphorically, symbolizing various forms of depletion – emotional, psychological, and societal – that each character undergoes. This thematic depth adds layers to the novel, pushing it beyond typical genre confines and challenging the reader to think critically about the nature of loss and despair.

However, the book is not without its challenges. At times, the detailed exposition, particularly in the early chapters, may feel overwhelming to readers eager to dive into the action. Furthermore, the vernacular used, though typically adding to the dark ambiance, occasionally borders on overwrought which might detract from the immediacy of the scenes depicted. Despite these minor setbacks, the novel's intricate plotting and strong character arcs mostly compensate, ensuring the reader's engagement is renewed with each chapter.

The element of the supernatural gradually introduced through the narrative hooks the reader with its originality and enigmatic allure. Loreweaver manages to blend traditional horror elements with fresh, imaginative twists, creating a hybrid genre piece that respects its roots while also offering new intrigues. The intertwining of Eleanor’s scientific approach with Marcus’s on-the-ground, instinctive detective work provides a riveting contrast, offering multiple lenses through which to view the mysteries presented.

What makes Exsanguination particularly standout is its bold refusal to provide easy answers. Just as the protagonists face obfuscations and setbacks, the reader is taken through a labyrinth of moral and existential quandaries. The conclusion of the novel, without venturing into spoilers, is both unexpected and thought-provoking, prompting contemplation long after the final page is turned. It’s a testament to Loreweaver's skill that the climax is both fulfilling yet leaves certain threads tantalizingly open-ended, perhaps hinting at a sequel or simply acknowledging that, much like in real life, not all tales conclude neatly.

In summation, G.R. Loreweaver's Exsanguination is a formidable entry into the genre, melding horror, thriller, and detective elements to create a novel that is as intellectually challenging as it is thrilling. The book should appeal not just to fans of horror or fantasy but to anyone appreciative of deeply atmospheric, character-driven narratives. Despite a slightly sluggish start and occasionally dense prose, the novel proves itself with a powerful storyline and robust character exploration, ultimately serving as a stark exploration of human (and inhuman) nature, with a lingering impact that haunts the reader well beyond its last words.